Air aspirating apparatus for heating or cooling buildings



Feb. 15, 1966 G. N. MILES ET Al- AIR ASPIRATING APPARATUS FOR HEATING ORCOOLING BUILDINGS Original Filed April 19, 1961 5 Sheets-Sheet lATTORNEYS Feb. 15, 1966 Q N, MlLEs ETAL 3,235,178

AIR ASPIRATING APPARATUS FOR HEATING OR COOLING BUILDINGS Original FiledApril 19. 1961 5 Sheets-Sheet 2 aff www? 4/ INVENTORS l (y F/G @T0/P5;-fv. /mff FRAN/r M 5,4/fy BYmzV/N a. me c tvari/v 4422, my

ATTORNEY Feb. l5, 1966 G, N, MlLEs ETAL AIR ASPIRATING APPARATUS FORHEATING OR COOLING BUILDINGS 5 Sheets-Sheet 5 Original Filed April 19,1961 Feb. 15, 1966 G. N. MlLl-:s ETAL AIR ASPIRATING APPARATUS FORHEATING OR COOLING BUILDINGS 5 Sheets-Sheet 4 Original Filed April 19,1961 Feb. 15, 1966 G. N. MILES ETAL AIR ASPIRATING APPARATUS FOR HEATINGOR COOLING BUILDINGS 5 Sheets-Sheet 5 Original Filed April 19, 1961INVENTORS United States Patent O 3,235,178 AIR ASPIRATING APPARATUS FORHEATING R COOLING BUILDINGS George N. Miles, Tenatly, Frank W. Bailey,Wayne, and Calvin D. MacCracken, Tenatiy, NJ., assignors to CalmacManufacturing Corporation a corporation o' New York Continuation ofapplication Ser. No. 116,902, Apr. 19, 1961. This application July 7,1964, Ser. No. 382,688 Claims. (Cl. 236-13) This is a continuation ofapplication Serial No. 116,902, tiled April 19, 1961, now abandoned.

This invention relates to air aspirating methods and apparatus forheating or coolingbuildings. More particularly, the present inventionrelatesV to air aspirating methods and apparatus wherein very hot air orvery cold air, which is supplied at high velocity from a suitableheating or cooling apparatus, is used to induce the flow of a muchgreater amount of air drawn from the building, and then the highvelocity air is mixed with the flowing room air to provide a largequantity of moving air at the desired comfortable moderate temperaturewhich is fed to the living space within the building to maintain acomfortable living temperature therein.

Air aspirating registers described as illustrative examples of thisinvention are well suited for thermostatic control for automaticallyregulating their own output in accordance with the temperature of theroom air and provide many important advantages in operation.

The air aspirating methods and apparatus of the present invention areparticularly intended to be used in a heating or cooling system in whichvery hot air or very cold air is supplied at a high velocity, that is,at an air ilow velocity of between 1,000 and 3,200 feet per minute. Forexample, in a heating system utilizing the present invention, the highvelocity air is supplied to the air aspirating register at a normaloperating temperature above 200 F. and usually less than 350 F. This hotair induces the flow of a much greater amount of room air and then mixeswith this moving yroom air to produce a large volume flow of air at thedesired moderate Warm temperature. As an example, it is noted that in acooling system utilizing the present invention, the high velocity air issupplied at a normal operating temperature below 55 F. and usually above35 F. and produces a large volume ow of air at the desired moderate cooltemperature.

In this high velocity type of heating or cooling wherein a relativelysmall mass of very hot or very cold supply air is mixed with a largermass of room air to produce the desired moderate temperature of airintroduced into the living space, the ratio of induced room air tosupply air, as measured on a weight-to-weight basis, should be more than1 to l. This ratio is called the aspirating ratio. When the aspiratingratio drops below this value of 1 to l, then the actual temperature ofthe air being introduced into the living space is usually too hot or`too chilly for comfort. Also, when the aspirating ratio drops below aratio of l to 1, undue variations and graduations in temperature occurthroughout the living space. In the case `of a cooling system, anaspirating ratio below 1 to 1 often causes the grille face covering theregister to become cooler than the dew point so that condensationappears on the grille face with resultant dripping and staining. Withthe higher aspirating ratios provided by the illustrative embodiments ofthe invention, the larger induced air flow maintains the temperature ofthe grille face above the dew point.

Among the many advantages of the illustrative examples of the airaspirating methods and apparatus of the present invention describedherein are those resulting from nce the fact that an aspirat-ing ratioof at least 1 to l is provided. Moreover, an aspirating ratio above 1 to1 is maintained under widely varying operating conditions, as will beexplained in detail further below'. As a result, a very comfortabletemperature is provided in the room adjacent to the point at which theair is introduced and undue variations or graduations in temperature inthe room are avoided under the widely varying operating conditionsencountered in actual usage throughout the year. t;

A further advantage of the aspirating registers described herein asillustrative examples of the invention is the low decibel mixing of thehigh velocity supply air with ambient air. These illustrative registersare adapted for mass production at relatively low cost while providingefficient operation in practical usage.

In accordance with the air aspirating methods and apparatus of thepresent invention, the high velocity supply air is ejected as a thinlayer passing through a long and relatively narrow orifice. An air iiowguide surface of special configuration extends from one side of thisoritice adjacent to the layer of high velocity air being ejectedtherefrom. This guide surface extends a substantial distance away fromthe orifice and provides a contoured face which effectively curvesbackwardly away from its initial direction near the orifice.Advantageously, this construction and arrangement of the special guide`surface holds the layer of high velocity air in clinging relationshipwith the guide surface and causes it to form a rapidly moving continuousfilm of air traveling along adjacent to the guide sur-face. The largemass of room air in which flow is to be induced is exposed to thisrapidly .moving film of supply air. As a result of the provision of thisback'- wardly curved guide surface, the high velocity layer of air isenabled to maintain its own identity with no significant mixing with theroom air and is enabled to maintain a relatively high velocitythroughout its extent as it travels along adjacent to the backwardlycurved guide surface. The room air becomes propelled along in thedirection of movement of the high velocity air by the velocity dragoccurring at the interface between the high velocity film of supply airand the slower moving room air.

By virtue of the `fact that the high velocity lm maintains its identityand maintains a high relative velocity throughout the extent of thecurving guide surface, the total area of the propelling interfacebetween the high velocity iilm and the room air is large. Moreover, thispropelling action is cumulative over the total extent of the highvelocity iilm. Consequently, a highly effective and advantageouscumulative total propelling action is provided for inducing the flow ofa much greater mass of room air, yielding an aspirating ratio of atleast 1 to 1 and usually considerably more under normal operatingconditions.

Among the many advantages provided by the illustraf `tive embodiment-sof the present invention described herein are those resulting from thefact that the amount of high velocity supply air ejected through theorifice is modulated directly at the orifice in accordance with re`quired amount of heating or cooling within the rooms. This modulation orcontrol of the high velocity supply air is obtained by changing theeffective size of the orice itself. By virtue of this modulation of thehigh velocity supply directly at the orifice, the aspirating ratio ismaintained and in most cases is actually increased as the amount of highvelocity supply air is reduced. This important advantage is in markedcontrast to the prior arrangements wherein a throttle valve or damper isused to restrict a duct leading to an orilice. In: such prior ar-lrangements, a partial closing of the damper valve causes :measure areduction in pressure in the duct between the damper and the orifice. Asa result, the velocity of the air through the orifice is reduced, andthe aspirating ratio drops to a lower value causing unduly hot or coldoutput.

In the illustrative examples of the present invention, a partial closureof the orifice actually produces a pressure rise in the pipe leading tothe orifice. This rise in pressure occurs because the pipe remainsunobstructed, while the total ow through the pipe is reduced, thusproducing a Smaller pressure drop in the length of pipe between thesource of the supply air and the orifice. Consequently, a reduction inthe effective size of the orifice produces an increase in pressureimmediately inside of the orifice with an advantageous increase in thehigh velocity of the air being ejected. This actual increase in velocityas' the flow is restricted serves to maintain an aspirating ratio ofmore than l to l and usually produces an increase in the aspiratingratio. Thus, the desired moderate temperature of the air being fed tothe room is advantageously maintained over a wide range of operatingconditions.

A f urther advantage of the illustrative embodiments of the presentinvention described herein results from the fact that only a relativelysmall movement of a control shutter serves to change the orifice fromits fully open to its fully closed position. For example, in theseillustrative examples of the invention, lthe full travel of the controlshutter is equal to 3/1@ of an inch or less. Thus, the actuation of thecontrol shutter is well suited for automatic operation by a thermostaticassembly as described.` Further, this construction provides completeshut-off, which is extremely desirable for quiet operation in a highvelocity system.

An additional advantage of the thermostatically controlled airaspirating register of the present invention is its highly `effectiveaction inAsensing the actual temperature ofthe air in the room in whichthe register is located.\ This register is compact, and the thermostaticcontrol assembly is included as an operating part of the register.Nevertheless, the thermostatic control assembly is isolated from thetemperature of the high velocity supply air and sensitvely responds tothe temperature of the air in the room When it is remembered that thesupply air is often at a temperature near 350 F., and yet thevthermostatic control assembly is isolated from this high temperatureand sensitively and accurately respends to slight changes in thetemperature of the room air, it will be appreciated how truly effectiveis its operation. The thermostatic control assembly has an air passagedirectly therethrough for the room air. The efficient aspiratingoperation of the apparatus throughout its wide range Vof operationassures that a large flow of the room air is always induced through thethermostat itself.

By virtue of the fact that the flow of supply air is modulated at theorifice, the aspirating ratio is maintained, and in some cases isincreased, even when the flow of the supply air is greatly reduced bythe shutter. Thus, a 'suiicient amount of room air is always induced toflow through the thermostat to provide accurate response to the actualtemperature of the room air. As a result, spurious responses totemperature of the nozzle either caused by transmission or convectionfrom the nozzle are desirably avoided.

This advantageous cooperative interaction of the air aspirator and itsthermostatic control assembly assures the desired temperature in theroom as set by the control knob' regardless of whether the apparatus isproviding maximum or minimum output.

Moreover, the air aspirating register shown as an illustrativeembodiment of this invention is enclosed in a casing only twelve inches(wide, twelve inches high and four inches deep so that it convenientlyfits between the 4studs of a partition or wall or in any similarclearance space in the wall of a room and requires an opening only fourinches deep. The construction is strong and adapted for reliableoperation and avoids complex fabrication so that it is well adapted formass production and for ease of installation.

In this specification and in the accompanying `drawings are describedand shown air aspirating methods and apparatus for heating or coolingbuildings as embodiments of the present invention and variousmodifications thereof are indicated, but it is to be understood thatthese examples are not intended to be exhaustive nor limiting of theinvention, but on the contrary, are given for purposes of illustrationin order that others skilled in the art may fully understand theinvention and the manner `of applying the methods and apparatus inheating or cooling systems so that they may modify and adapt variousforms, each as may be best suited to ythe conditions of a particularuse.

Although the air aspirating methods and apparatus embodying the presentinvention are described with particular emphasis upon heating systems,it is intended to be understood by those skilled in the art that this isfor convenience of explanation of the many operating advantages underdemanding and severe conditions of usage, and operating advantages of asimilar nature are provided by utilizing the air aspirating methods andapparatus of this invention in a cooling system or air conditioningsystem for a building. In this 'specification the phrase hot air supplyor similar term as applied when considering a heating system is intendedto include the corresponding phrase cold air supply or similar term asapplied when considering a cooling or air conditioning system; likewisethe term warmer is intended to include the corresponding term coolerfThe various objects, aspects and advantages of the present inventionwill be more fully understood from a consideration of the followingdescription in conjunction with the accompanying drawings, in which:

FIGURE l is a front elevational view of a thermostatically controlledair aspirating register embodying the present invention, with a portionof the face plate shown broken away to reveal certain features ofconstruction. This figure is drawn to a scale of one-half showing thisembodiment of the invention as one-half its actual size;

FIGURE 2 is a front elevati-ouai View of the lower portion of the airaspirating apparatus of FIGURE l drawn on the same scale as FIGURE l,with the face plate removed to disclose the nozzle construction;

FIGURE 3 is a vertical sectional view of the air aspirator of FIGURE 1taken along the centerline 3 3 and being drawn to a scale whichillustrates the apparatus at four-fifths of its actual size;

FIGURE 3A illustrates a modified grille face;

FIGURE 4 is a partial sectional view taken along the line 4 4 of FIGURE3 showing the aspirator mounting arrangement at one side of the casing;

FIGURE 5 is aV partial sectional view taken along the line 5 5 of FEGURE3 illustrating the construction at the lower end of the casing, beingdrawn `on a reduced scale from FIGURE 3;

FIGURE 6 is a partial sectional view taken generally along the line 6 6of FIGURE 3 and shown on a scale of twice actual size to disclosefeatures of construction and operation of the thermostatic controlassembly;

FIGURE 7 is a partial sectional view of the thermostatic controlassembly taken along the line 7 7 of FIG- URE 6;

FIGURE 8 is a cross sectional View of the thermostatic control assemblyon the line 8 8 `of FIGURE 6;

FIGURE 9 is an end view of the cam element of the control knob, as seenlooking along the line 9 9 of of FIGURE 6, and shown on a scale of oneand threeiifths actual size;

FIGURE l0 is an axial sectional view of the cam element on the line Miii of FlGURE 9;

FGURE ll is an axial sectional exploded View of parts of thethermostatic control assembly including the cam element as seen alongthe line 11-11 of FIGURE 9;

FIGURE 12 is a partial vertical sectional view of another embodiment ofthe present invention adapted to be controlled manually;

FIGURE 13 is a schematic diagram for illustrating certain of theprinciples and advantages of the air aspirating apparatus of the presentinvention; and

FIGURE 14 shows further details of a shutter assembly for controllingthe air flow.

As illustrated in FIGURES 3 and 14, in the air aspira*- ing methods andapparatus of the present invention, the high velocity supply air isejected as a thin layer passing through a long and relatively narroworifice 22. The high velocity air forming the layer 2f) is supplied froma suitable heating or cooling apparatus, as the case may be, for heatingor cooling a building. The layer 20 is ejected in an initial directionas indicated by the arrow 24 adjacent to an extensive air flow guidesurface 25 of special conguration, as will be explained. This guidesurface 26 extends a substantial distance away from the orifice 22 andprovides a contoured face which effectively curves backwardly away fromits initial direction near the orifice. In the preferred embodiment ofthe invention, the initial area 27 of the guide surface 26, which isadja cent to the emerging high velocity layer 20, serves to define oneside of the long narrow orifice 22. The other side of the orifice 22 isdefined by a lip 28 spaced substantially uniformly away from the area 27along the length of the orifice.

This initial area 27 of the guide surface at the narrowest throat of theorifice 22 is directed substantially tangential to the direction 24 ofthe emerging high velocity layer 24, and begins curving backwardly justoutside of the orifice 22.

Thus, it will be appreciated that this initial area 2'7 of the guidesurface provides a `convex face or bulging contour which divergesbackwardly farther away from the initial direction 24 of the highvelocity layer as the guide surface continues outwardly away from theorifice 22. As the high velocity layer 20 passes by this bulging contournear the orifice, a reduced pressure is created adjacent to the face ofthe guide surface 26, and the layer 20 is caused to cling to this guidesurface and forms a rapidly moving continuous film of air 30 travellingalong adjacent to the guide surface 26. This guide surface 26effectively continues to curve backwardly as the film 3f) travelsfurther away from `the orifice.

Thus, the lm 30 is continuously travelling over a surface which` iseffectively convex as measured in the direction of flow 32 of the film30, and consequently, the reduce-d pressure adjacent to the guidesurface extends substantially throughout its extent beneath the film 30.The consruction and arrangement of the guide surface 26 holds `the film30 in clinging relationship therewith.

The large mass of room air 34 in which flow is to be induced is exposedto this high velocity film 3i) over the extensive area of the film 3f).Advantageously, the film 30 maintains its own identity with nosignificant mixing with the room air, and thus it is enabled to maintaina relatively high velocity as `it travels along adjacent to the guidesurface 26. The room air becomes propelled along in the direction ofmovement of the film 3f) by the frictional viscous velocity dragoccurring at the interface 36 between this high velocity film of supplyair and the slower moving room air.

It is an advantage of the methods `and apparatus of this invention thatan aspirating ratio of at least 1 to 1 is provided because the totalarea of the propelling inter face 36 is large. Moreover, the film 30 istravelling at a high velocity so as to produce a substantial componentof velocity drag at every elemental area of the interface, and thisvelocity drag is cumulative in effect, thus producing a highly effectivepropelling action.

The room air 34 enters in an inlet zone 38 in the vicinity .of theorifice 22 and is propelled along beside the interface 36 as indicatedby numerous flow arrows 40. As the film 30 nears the far limit 41-of theconvex guide surface 26, it strilces an inclined bafiie 99 and isdeflected toward an outlet zone 42. The high velocity supply air fromthe film 30 becomes thoroughly mixed with the moving room air 4l) afterthe film 3f) has reached the limit 4l of the guide surface `as they movetogether toward the outlet zone lf2. As a result, a uniform moderatetemperature is provided at all points near lthe outlet zone 42.

In most installations it is found to be preferable to rave a greatercurvature Ior bulge, ie., a more rapid change in direction, in theinitial area 27 of the guide surface 26, as compared with the curvatureof the guide surface at points more remotion from the orifice 22. Thisinitial bulge at 27 is immediately adjacent to the discharge path 24from the orifice 22 and stabilizes the fast moving layer of air 20assuring that this layer will begin clinging to the guide surfaceimmediately after leaving the orifice so as to form the stable fastmoving film 30 travelling along the guide surface. Thereafter, lareduced curvature is usually found to be sufficient to hold the film 30close to the guide surface 26 and maintain this film continuouslyadjacent to the guide surface. In other words, the initial bulgingcontour at 27 creates a low pressure region adjacent to the guidesurface 26 and assures stability in the film 30. fn `certaininstallations where the velocity of the ejected layer is low, then thisinitial curvature can be reduced so that the effective curvature of theguide surface is more uniform throughout, but in most installations itis found to be preferable to have the initial region 27 of increasedcurvature as compared with the average curvature throughout the area ofthe guide surface 26. Also, where particular flow patterns are requiredin the film, other areas remote from the orifice and having a greatercurvature than the average curvature of the guide surface can beincorporated. However, using a guide surface having an initial area withgreater curvature than the curvature of the remaining area has beenfound to be the most `satisfactory under widely varying conditi-ons -ofoperation and thus is preferred as shown.

The thermostatically controlled air aspirating register 41 as shown inFIGURES l, 2 and 3 is a preferred embodiment of the present inventionland is adapted to be installed in the space between adjacent studs in awall or partition of a room to be heated or in any similar vclearancespace or opening in a wall or partition. In these figures the outsideport-ion of a room wall or partition is indicated at 43, and the back`portion is indicated at 44. The face plate or grille face 46 of the airaspirating register is providedwith inlet and outlet openings, which maybe of any shape, such as inlet louvre openings .38 and outlet louvreopenings 42. The casing or box 48 of the air aspuating register islocated within the wall, and the face plate 46 is secured to the casing48 by screws 49 which also serve to secure the casing to the Wall 43, asbest shown in FIGURE 3. Around its perimeter the face plate 46 seatsagainst a resilient gasket 5G formed of suitable material, for example,grey polyurethane.

In order to provide for thermal insulation and sound absorbency withinthe casing 4S, a layer of acoustical and thermal insulation 52 issecured to the interior surfaces of the casing and to the inside surface-of the lower portion of the face plate 46 below the inlet louvreopenings 38.l As an example of a suitable material for the insulationlayer 52, it is noted that a layer of fine glass fiber board applied bycement works to advantage. As shown in FIGURE 2, this insulation 52 isalso affixed to the inner surface of both end plates 53 and 54 of thecasing.`

The air aspirator 56 is positioned within the casing 48 and includes anozzle portion 25 together with thecurving high velocity air flow guidesurface 26 extending from the nozzle and contoured and arranged similarto the construction illustrated in FIGURE 14. The: nozzle portion 25 ofthe aspirator has certain advantages as will be described further belowand operates to receive the incoming supply of high velocity air 58 in ashort neck 59, which is here shown as protruding slightly through asuitable opening 60 in the bottom plate 62 of the casing 48.

In most installations it is found to be more convenient to position thecasing 48 as illustratively shown, with the neck 59 of the nozzle at thebottom. Accordingly, for convenience of reference, the plate `62 -iscalled the bottom plate of the casing, and the other parts are describedin terms of the illustrative orientation as end, lower or ,upper, etc.However, there are numerous instances where the building structure andlayout will require that the neck 59 of the nozzle be oriented at thetop of the easing or at the left or right. It is an advantage of thisair aspirating register that it can be positioned in any desiredorientation and will operate in a highly satisfactory manner regardlessof its orientation. r[he vertical position as illustrated is the usualoperating position, but as indicated above, the operation of theapparatus is not limited to any particular position.

The neck 59 of the nozzle is adapted to the coupled to a suitable pipeor small diameter duct 64 surrounded by an insulation covering 65 andadapted to carry the high velocity supply air 58. In most installationsit is found desirable to utilize an insulated tlexible pipe or duct 64,for example, such as is disclosed in U.S. Patent No. 2,936,792. In thispreferred example of an air aspirating register, the neck 59 is shown ashaving an outside diameter of 2.0 inches for connection to a duct 64having a corresponding I.D. For purposes of securing the insulated duct64 to the casing, a collar 66 tightly embraces the end of the ductinsulation 65 and has a tiange 68 afiixed to the casing bottom plate 62.The opening 66 is sufficiently large to allow the insulation 65 toprotrude into the casing 48 to provide an air-tight fit with the neck59.

In order to distribute the incoming high velocity supply air 58 quietlyand uniformly to all points along the narrow orifice 22, the interiorsurfaces 70 of the walls 72 of the nozzle portion 25 are smoothlyrounded in all directions and polished, as seen in FIGURES 2 and 3, andsharp edges or breaks are eliminated. As indicated in FIGURE 2, theseinterior surfaces 70 include contiguous reverse curves which aresubstantially tangential with the throat of the orifice 22. Toward isopposite ends the interior surfaces 70'define oval passages extendingout to the end of the orifice 22 as'seen in cross section in FIGURE 3,for this shape has been found to provide am le fiow of high velocitysupply air fully out to the end of the orifice, while enablingconstruction of a compact over-all nozzle.

To provide the desired flow capacity for the high velocity supply airand at the same time to provide the required exit velocity formaintaining the high aspirating ratio of at least 1 to 1 discussed aboveunder widely varying conditions of operation as encountered in actualusage, the orifice 22 preferably has a length of at least six inches andno more than eighteen inches when used with a supply duct 65 with an ID.of between 1.5 and 2.75 inches. In a preferred embodiment constructedIin accordance with the present invention as shown for use with a duct64 having an an ID. of 2.0X inches, the orifice 22 is 11.0 inches long.It will be understood that the length of the orifice 22 and theconfiguration of the throat of the orifice may be varied somewhat,although the particular dimensions and construction described have beenfound to tbe very satisfactory in testing under widely varyingconditions of operation in many different types of buildings.

A pair of arcuate smoothing varies 74 are positioned within the nozzle74 to prevent any tendency for the flow of the high velocity supply airto concentrate out toward the ends of the orifice. These arcuate vanesor baffles 74 serve to capture and direct the required proportion of thehigh velocity ow toward the center region of theorifice 22, and thus,the vanes 74 assure a uniform over-all distribution of the ejected layer2G issuing at all points along the orifice. The downstream ends 75 ofthese varies '74 are spaced with respect to the length of the orifice 22so as to divide up the interior space of the nozzle near the oriiice 22into three substantially equal parts. ln the preferred example as shownwith an orifice 11.0 inches long, the downstream ends 75 are spaced 4.()inches apart and are each 3.5 inches from the respective ends of theorifice. The interior surfaces 70 of the nozzle are smooth with sharpprojections being avoided.

For making a nozzle 25 having the desired shape and smooth interiorconfiguration as described above, a preferred construction for thenozzle as shown is to fabicate it from two substantially identical diecast halves 25A and 25B having an air-tight joint 77 therebetween formedby mating fianges 78. These halves are internally polished and aresecured together `by suitable fastening means 75, for example by machinescrews.

To position the initial convex area 27 of the air flow guide surface 26closely adjacent to the high velocity layer 2d being ejected from theorifice while minimizing the vover-all size of the aspirator, theupstream edge 86B of this guide surface overlaps the interior surface ofthe lip 29 and is secured by suitable fastening means directly to theinterior surface of the lip 29 of the nozzle at a position spacedupstream away from the throat of the orifice. In this preferredembodiment, three very small metal metal tapping screws 81 are used.These screws 8l are positioned a substantial distance upstream from thethroat or narrowest part of the orifice so that their heads do notdisturb the air flow out through the orifice. If desired to pla-ce thesescrews nearer to the throat of the orifice, their heads may becountersunk. Also, if desired to locate the edge St) nearer the throat,a small longitudinal recess or rabbet in the lip Z9 may be provided, asshown at 82 the modified register 39A of FGURE l2, into which the edge8@ fits with its exposed surface flush with the inner surface of the lip29. However, the construction as shown is found to operate quitesatisfactorily in actual practice.

In order to facilitate the convenient mounting of the nozzie 25 withinthe casing 4S, the opposite ends or wings S3 of the nozzle includemounting lugs 84 adapted to engage in a pair of spring mounting clips 85secured t0 the opposite end plates 53 and 54 of the casing. As seen bestin FIGURE 4, each mounting clip 85 has a generally L-shape including along resilient inclined leg or ramp 86 spot welded to the end plate 54near the front of the casing, and a lateral leg 87 spaces the inner endof the inclined leg away from the end plate.

For rconvenient installation of the nozzle 25 within the casing 48, theneck 59 is first inserted down through the opening 6l), and then themounting lng 84 at each end is slid inwardly, as shown by the arrow inFIGURE 4, along the spring ramp S6. The ramp 86 is detlected outwardlyas indicated in broken outline until the lug 84 becomes aligned with ahole 88 in the ramp, at which instant the ramp 86 snaps into positionaround the lug 34 so as to lock the nozzle in position. rThe neck 59 isheld in the desired position within the opening 60 by a notched clip 89which engages the abutting ilanges 78 on the halves of the nozzle at thejoint 77. Thus, the position of the nozzle within the casing isaccurately determined, and the nozzle is held firmly in place by threepoints of support, namely, at the two mounting lugs 84 and at the clip89.

In the illustrative preferred embodiment of an air aspirating registerfor installation in the wall, the air flow guide surface 26 is formed ofsheet material, shown as sheet metal, and it extends to a limit 41 nearthe outlet zone defined by the openings 42. This limit 41 is shown asbeing formed by a bend in the sheet metal with a sloping baffle portion90 extending up to be secured to the top plate 91 of the housing 4S nearthe front. When the high velocity film 30 and the moving room air 4dmeet the inclined bafiie 90, a thorough turbulent mixing Q. occurs asthey move toward the outlet d2, thus assuring uniform temperature in theoutput air mixture 92.

As shown in FIGURE 3, the outlet louvre openings 42 are sloped upwardlyand outwardly substantially parallel with the inclined baiile 9G. Whenthe aspirating register 39 is used in position with the nozzle at thetop, as illustrated schematically in FlGURE 3A, then it is sometimesfound desirable to have the louvre outlet openings 42A `slope in thedirection as the inlet openings 38. Thus, the outlet openings 42A aregenerally perpendicular to the baille 9@ and serve to deflect the outputmixture 92 upwardly and outwardly.

When utilized in a cooling system, it is preferable to apply a bailleface moisture absorbent liner 93 to the sloping baffle 9i). This catchesany condensed moisture which may appear during the initial cooling orpull down period of operation. Thereafter, the moisture is re-evaporatedin the output air flow 92. A suitable material for the absorbent liner93 is a layer of grey polyurethane sponge at least one-quarter of aninch thick.

A thermostatic control assembly 94 accurately and sensitively respondsto the temperature of the room air 3d and controls the effective widthof the orifice 22. This thermostatic assembly includes a manuallyadjustable knob 95 for setting the desired temperature within the roomas indicated by a room temperature setting scale 96, which is displayedon a yraised rectangular panel 97 surrounding the axis of the assembly9d and held by a -pair of mounting screws 98 secured to the face plate16. The knob is open to admit a substantial induced flow 1d@ of room airthrough the thermostatic assembly 94 for sensing room air temperature. Atriangular web 1112 within the air passage through the knob denes aneasy-to-read pointer which is read in conjunction with the scale 96.

In order to control the iiow, a shutter element a is slidably mountedupon a sloping outer surface or seat 195 which is inclined to thecentral plane of the nozzle as defined by the joint 77 so that movementof the shutter element effectively changes the width of the orifice.This sloping seat 165 is formed by the inclined outer face of the lip 28in conjunction with a plurality of spaced inclined shoulder fins 166which are integral with the nozzle wall 72 and are contiguous with theinclined outer face of the lip 23. At the opposite ends of the nozzleare a pair of spaced flanges 19S forming parallel guides engaging theends of the shutter element. These flanges 163 have bearing openingstherein for rotatably supporting the opposite ends of a shutter bar115i.

During changes in the operating position of the thermostat, the shutterbar 111i is rotated by movement of a flexible wire cable 112, as seenbest in FIGURES 6 and 7. A pair of shutter cranks 11d slide the shutterelement 1114 upon its seat 105. These cranks 11d are rigidly secured tothe rotatable bar 11d by suitable fastening means shown as set screws117 (FIGURE 6). At the end of each crank 114 is an articulated couplingfor operatively connecting the crank to the shutter element 1ML. In thisexample, the articulated coupling means comprise a rounded element orpin 116 engaging in a slotted socket member 113 on the shutter element.A bowed leaf spring 119 lies between the pin `116 and the back of theshutter element for pressing the shutter element firmly down against itssloping seat 105.

The shutter element 1M comprises a rigid backe-r plate 124), shown as arigid metal strip. The socket 11S is formed by a pair of closely spacedtabs, as seen in FlG- URE 14, which are struck out from the backer plate126i and are bent up perpendicular to it. The leaf spring 119 is slottedand surrounds both of the tabs of the socket so that it cannot slip outof place beneath the crank pin 116. A soft flexible acousticallyabsorbent liner 121 is beneath the hacker plate 129 and bears downagainst the seat 1115. To provide a low coefficient of friction, thisfelt liner is preferably formed of a slippery ber, for example, a feltof Teflon polytetrafluoroethylene fiber is found to be 10 advantageous.The soft flexible edge of the liner 121 extends beyond the edge of thehacker plate, and when the shutter is closed, it is this flexible edgeof the liner which abuts against the convex air flow guide surface 27,thus assuring a complete closure and quiet shut-off of the air ilow.

ln this illustrative embodiment of the invention, the temperaturesensing element 122 is a Vernatherm element which is obtainedcommercially from Detroit Controls Corporation. Changes in thetemperature of the room air 1d@ passing through the thermostatic controlassembly cause an expansion or contraction of a pliable material 123within the element 122. The result is that an increase in temperaturecauses a piston 124 to move to the left out of its cylindrical 126. Thismovement of the piston 12a slackens the cable 112, and a torsion spring128 (FIGURE 2) rotates the shutter rod so as to slide the shutter tofurther reduce the orifice. Conversely, a decrease in room airtemperature correspondingly further opens the orifice.

The cable is fastened to a piston head 130 attached to the end of thepiston rod 124. A tension spring 132 is connected between the barrel ofthe cylinder 126 and the piston head 130 for purposes of retracting thepiston rod against the pliable material within the cylinder 126 when thetemperature of the sensing element 122 is reduced.

The sensing element 122 is fxedly screwed into an adjustable support 134having a pair of oppositely twisted cam follower blades 13o and 137projecting therefrom in sliding engagement with annular cam surfaces 138and 139, respectively, of a hollow cylindrical cam member 14d (FIGURES 9and 10). The knob 9S is fastened to the cam element 14d by a set screw141.

Manual rotation of the knob causes a corresponding rotation of the camelement 140, and the cam action of the two cam surfaces 138 and 139against the follower blades 136 and 137 serves to move the support 134toward or away from the shutter bar 111 to produce the desiredtemperature setting at which the .register 39 will automaticallymaintain the room. The cam element 141) is rotatably supported by meansof a ring mount 142 secured to a pair of parallel struts 14d which havesemicircular recesses engaging a pair of Teiion bushings 146 looselyfitting on the shutter rod 111i.

In order to prevent rotation of the adjustable support 13d whilepermitting its adjustment toward and away from the shutter bar 111i, thestruts 144 have channels 147 therein engaged by projecting bent tabs orkeys 148 on the adjustable support 134. A locking ring 15) holds the camelement in place on its ring mount 142. A pair of stop lugs 151 (FGURE9) on the interior of the cylindrical cam element 1li@ bump against thetabs 14S upon rotation of the knob @5to its extreme positions so as tolimit the rotation of the knob over an arcuate range of travel ofslightly less than 189 corresponding with the arc of the temperaturescale 9d and with the cams 133 and 139.

In the modified air aspiratng register 11A of F1C- URE 12, the positionof the shutter element 11i-i is adjusted by a manually operable lever152 projecting through a slot 154 in the register face plate de. Thislever is directly connected to the shutter bar 110. It `will beunderstood that parts of this modified air aspirating register of FEGUREl2 performing functions corresponding with those of other figures havecorresponding reference numbers.

in FGURES 2, 3 and l2 is shown a stop 156 adjustable in position andheld by a screw 158. This stop has an elongated slot surrounding thescrew and the stop nests between two parallel ridges 159 on the nozzlebody. Vertical adjustment of this stop serves to limit the full openmovement of the shutter element at a position less than the full widthof the orice in the nozzle 25 as may be desirable for smaller rooms.Also, for registers d1 or 4lA which are located near to the source ofsupply air, it may be desired to limit the full open position of theshutter for reducing the maximum possible flow of the supply air. Ascale 15) is provided on the nozzle adjacent to the lower end of anadjustable stop i556 to help in selecting the desired position for thisstop.

The efficient operation of these aspirating registers as describedherein provides a low decibel mixing of the extreme temperature highvelocity air with the ambient air. Moreover, any sound which may begenerated by the aspirating register is radiated from the orifice 22 andis in the upper portion of the audio frequency sound is quitedirectional in its radiation pattern. As shown in FIGURE 3, 3a, and l2,the orifice 22 is advantageously positioned in offset relationship withrespect to the inlet and outlet openings 38 and i2 in the grille face.The inlet and outlet openings 33 and 4t2 are closely adjacent andlocated generally in the upper half of the casing i3 whereas the nozzle25 and orifice 22 are located generally in the lower half of the casing.Thus, there is a solid portion of the grille face which extends acrossin front of the orifice 22 which blocks any high frequency sound fromdirect radiation into the room. in addition, this solid portion of thegrille face supports an area of the sound absorbent material :T2 whichabsorbs a large pro portion of any sound from the orifice 22.

It is found that increasing the vertical height of the register furtherincreases the aspirating ratio. Thus, for special installations where aneven larger aspirating ratio is desired, a larger register with a moreextensive guide surface 26 and more extensive inlet and outlet openings3S and 42 may be used. For most installations the illustrative registersare found to work very satisfactorily in providing the describedadvantages. lt is to be noted that the present invention enables theconstruction of a compact highly effective register. The illustrativeexamples are one foot square in face area and less than four inches deepand produce desirably moderate, substantially uniform output air over avery wide range of operating conditions with input air at high velocityand extreme temperature and automatically regulates itself in a veryeffective manner from full closed to full open position. Moreover, anypartial closure of the shutter produces an increase in aspirating ratio.

The illustrative embodiments of the invention are readily adapted foruse in cooling systems. For example, the flexible cable lf2, shown inFGURE 6, is Wound in the opposite direction around the rotatable rod il@so that with reference to FGURE 7 the cable is arranged in the modifiedcooling register to extend tangentially from the top of the rod 112.Also, the centerline of the thermostatic control assembly 9d is raisedto be aligned with the cable where the cable extends from the top of therod lill. A convenient way to raise the centerline of the thermostaticcontrol assembly 94 is to turn it upside down. lt will be noted that therecesses in the ends of the struts 144 which engage the bushings M5 onthe rod llt) are offset from the centerline of the assembly 94. Thus,the assembly is adapted to be utilized for cooling control by turning itupside down with a reverse wound cable as discussed, and appropriatechanges are made in the scale ile as will be understood.

From the foregoing it will be understood that the air aspirating methodsand apparatus of the present invention described above are well suitedto provide the advantages set forth, and since many possible embodimentsmay be made of the various features of this invention and as the methodand apparatus herein described may be varied in various parts, allwithout departing from the scope of the invention, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense and that in certain instances some of the features of theinvention may be used Without a correspondlif) ing use of otherfeatures, all Without departing from the scope of the invention.

What is claimed is:

l. Air aspirating apparatus for maintaining a building at a comfortableliving temperature by supplying to an Outlet air at an extremetemperature mixed with a greater amount of air induced to i'iow alongtherewith, comprising a casing having an inlet for said induced airiiow, a nozzle adapted to be connected to a source supplying air at highvelocity and extreme temperature and having a long and narrow orificefor ejecting a narrow layer of the high velocity supply air outwardlyfrom said nozzle in an initial direction, a continuously curved convexair flow guide surface extending from one side of said orifice tangentto the layer of high velocity air being ejected from said orifice, saidconvex guide surface commencing immediately adjacent to said orifice andextending away from said orifice and providing a continuously curvingface diverging backwardly away from said initial direction at anincreasing angle at progressively greater distances from said orificefor continuously holding said high velocity layer of air closelyadjacent to said curving guide surface forming a high velocity film ofair of extreme temperature clinging to said curving guide surface andtravelling rapidly therealong, said curving convex guide surfacecontinuing to a position near to said outlet and remote from saidorifice, said orifice and curving guide surface being located in saidcasing in cooperative relation to said inlet for exposing said highvelocity clinging film of air to the induced air entering said inlet,and said inlet being directly in front of said convex guide surface andbeing of extensive area in proportion to the area of said convex guidesurface, thereby propelling a greater amount of induced air along besidesaid high velocity film toward said outlet.

2. Air aspirating apparatus for maintaining a building at a comfortableliving temperature by supplying an outlet with air of extremetemperature rnixed with a greater amount of air drawn from the building,comprising a casing having an inlet for the air drawn from the buildingand an outlet for supplying the air mixture to the building, a nozzleadapted to be fed with supply air of high velocity and extremetemperature, said nozzle having a long and narrow orifice for ejectingthe supply of air as a fast moving layer, said orifice extendingparallel to the front of said casing near to said inlet, and aneffectively curved convex guide surface extending behind both said inletand outlet, said convex guide surface extending outwardly away from saidnozzle from a position adjacent to said orifice, said inlet and outletbeing in the front of said casing and immediately adjacent one toanother and defining a maior proportion of the frontal area of saidcasing directly in front of said convex guide surface, said guidesurface having an area initially tangent to the direction of ejection ofthe supply air from said orifice and continuously curving backwardly asit continues from a position near said inlet to a position near saidoutlet and said initially tangent area near said orifice being ofgreater curvature than the area of said guide surface more remote fromsaid orifice.

3. Air aspirating register apparatus for maintaining a building at acomfortable living temperature by supplying an outlet with air ofextreme temperature mixed with a greater amount of air drawn from thebuilding, comprising a casing having a front face including an inlet forthe air drawn from the building and an outlet for supplying the airmixture to the building, a nozzle adapted to be fed with supply air ofhigh velocity and extreme temperature, said nozzle having a long andnarrow orifice for ejecting the supply air as a fast moving layer, acontinuously curved convex guide surface having an initial region ofgreater curvature adjacent to 4and defining the back side of saidorifice, said initial region being tangent to the direction of ejectionof said supply air and said convex guide surface extending away fromsaid orifice for a substantial distance whilecontinuously curving in aconvex direction with respect to the front face of said casing, saidfast moving layer of supply air clinging to said guide surface as saidsupply air rapidly moves away from said orifice and forming a fastmoving film travelling along adjacent to said curved guide surface, saidinlet and outlet forming a major proportion of the total area of thefront face of said casing directly in front of said curved convex guidesurface for exposing a large mass of the -building air to said fastmoving film for propelling the building air to `a position near saidoutlet, and an inclined baffle near said outlet positioned at an abruptchange in direction with respect to said curved convex guide surfacedefining the outward limit of said guide surface and being inclinedtoward said outlet for turbulently deflecting the supply air from saidfilm toward said outlet for mixing with the air drawn from the building.

4. Air aspirating register apparatus as claimed in claim 3 and whereinsaid inclined baiiie has a liner of porous moisture absorbent materialthereon for collecting condensed moisture during initial periods ofoperation of said register apparatus and for retaining said moisture forsubsequent re-evaporation after said initial period has passed.

S. Thermostatically controlled aspirating register apparatus formaintaining a building at a comfortable living temperature by supplyingair to an outlet at extreme temperature mixed with a greater amount ofair drawn from the building, comprising a casing having an inlet for theair drawn from the building and an outlet for supplying the air mixtureto the building, a nozzle adapted to be fed with supply air of highvelocity and extreme temperature, said nozzle having a long and narroworifice for ejecting the supply air in an initial direction as a fastmoving layer, a fixed curved concex guide surface defining one side ofsaid narrow orifice and initially extending outwardly away from saidorifice in the same direction as the initial direction of the ejectedair and progressively curving backwardly providing a convex surface forretaining said fast moving layer against said guide surface as a filmtravelling therealong, said guide surface extending from a position nearsaid inlet to a position near said outlet, a shutter element movablymounted in said nozzle, said shutter element being positioned on theopposite side of said orifice from said convex guide surface and beinginclined at a large angle to the initial direction of the ejected air,said shutter element having one edge thereof normally spaced a smalldistance from said convex guide surface for movement toward and awayfrom said convex guide surfa-ce for progressively restricting the widthof said orifice, and thermostatic means in said inlet connected to saidshutter element for moving said edge of the shutter element toward andaway from said convex guide surface.

6. Controllable aspirating apparatus for maintaining a room at acomfortable living temperature by supplying air of extreme temperaturemixed with a greater amount of air drawn from the room, comprising anozzle adapted to be fed with supply air of high velocity and extremetemperature, said nozzle having a long and narrow orifice of a widthless than 1A: of an inch for ejecting the supply air as a fast movinglayer, a continuously curved convex guide surface extending outwardlyaway from said nozzle from an initial area adjacent to one side of saidorifice, a sliding shutter element slidably mounted in said nozzle onthe opposite side of said orifice from the initial area of said curvedguide surface defining the orifice between an edge of said slidingshutter element and said convex guide surface, and control means forprogressively sliding an edge of said shutter element toward saidinitial area of the guide surface for progressively decreasing the widthof said orifice while maintaining an aspirating ratio greater than l tol.

7. Adjustable aspirating apparatus for maintaining a building at acomfortable temperature by mixing air of extreme temperature with agreater amount of ambient air comprising a nozzle for receiving airsupplied at high velocity and extreme temperature, said nozzle beingsymmetrical about a central plane and having a narrow elongated orificealigned with said central plane for ejecting a thin sheet of the supplyair, a curved convex air flow guide surface extending away from saidorifice and having an initial area closely adjacent to one side of saidorifice, said initial area of the convex guide surface -having a bulgingcontour adjacent to said thin sheet of supply air for stabilizing theejected sheet of supply air and Icausing the sheet of supply air tocling to said convex guide surface and to travel therealong as a fastmoving film, a shutter slidably mounted on the nozzle on the oppositeside of said orifice from said curved convex guide surface, said shutterbeing inclined to said central plane with one edge of said shutter nearto said bulging contour for defining at the outlet of said orifice thenarrowest opening thereof between said edge and said bulging contour,and control means for sliding said shutter toward and away from saidbulging contour for varying the spacing at the outlet of said orifice.

8. A thermostatically controlled aspirating register for maintaining aroom at a comfortable temperature by feeding to an outlet a mixture ofair at extreme temperature mixed with a greater amount of air drawn fromthe room for thermostatically controlling the amount of air at extremetemperature in response to the temperature of the air being drawn fromthe room comprising a casing having a grille face with a wide inlet forroom air extending over the center of the grille face and a wide outletfor the mixed air extending over one end of the grille face, a nozzlenear the other end of the casing adapted to be fed with supply air ofhigh velocity and extreme temperature, said nozzle having a narrowelongated orifice for ejecting a sheet of supply air therefrom at highvelocity, a curved convex guide surface extending from one side of saidorice past said inlet and toward said outlet for holding the sheet ofsupply air in clinging relationship with said convex guide surface, saidgrille face having a panel area extending directly in front the orificefor blocking the direct radiation of sound from the orifice into theroom, a shutter member movably mounted for progressively restrictingsaid orifice, and a thermostatic element for sensing the temperature ofthe room air mounted near the center of said panel area for controllingsaid shutter member, said panel area having an opening therein adjacentto said thermostatic element for admitting a iiow of the room airthereto.

9. An aspirating register for maintaining a room at a comfortabletemperature thermostatically controlled in response to the temperatureof the air being drawn from the room comprising a casing having an inletand an outlet, a nozzle adapted to be fed with supply air of highvelocity and extreme temperature and having a long narrow orifice with acurved convex gui-de surface extending from one side of said orifice forproviding a film of supply air flowing along said convex guide surfacearranged to create an induced flow of room air into the register throughsaid inlet, said register providing a mixture of the room air and supplyair from said outlet, a thermostatic element adjacent said inlet forsensing the temperature of the room air in said induced flow, and aslidable shutter member slidably mounted in said register directly atthe outlet of said orifice for moving an edge of said shutter elementtoward said convex gui-de surface and controlled by said thermostaticelement for modulating the width of the outlet of said orice, wherebythe aspirating ratio is maintained when the orifice is restricted forassuring adequate induced flow of room air, thereby providing accurateresponse of the thermostatic element to the temperature of the room airthroughout the full range of operation of the register.

10. Air aspirating apparatus for mixing supply air of extremetemperature and high velocity with room air to provide a mixture ofmoderate temperature for feeding to a room comprising a casing adaptedto be mounted in the Wall of a room and having a large opening in thefront thereof facing toward the room, a nozzle mounted in one end ofsaid casing and having a long and narrow orifice directed toward theinterior of said casing into the region behind said large opening, acurving convex guide surface defining the rear side of said orice andextending across said casing toward the opposite end thereof, saidnozzle being adapted to discharge the supply air through said orice forforming a high velocity film travelling along adjacent to said convexguide surface, said convex guide surface extending behind said largeopening With its convex surface facing toward said large opening andsaid large opening extending `directly in front of a major portion ofsaid curving convex surface for inducing the 110W of room air into saidcasing through said large opening by the velocity drag action of saidhigh velocity film, and a deliector at the far end of said convex guidesurface for deecting said mixture into the room.

1 6 References Cited bythe Examiner UNITED STATES PATENTS 1,878,0129/1932 Stacey et al. 165-123 2,345,537 3/1944 Keep 165-123 2,432,289 12/1947 Dauphinee 98-4O 2,490,379 12/ 1949 Schlumbohm 62-281 2,523,4979/1950 Copping 236-49 2,680,355 6/1954 Colomb 62-281 X 2,821,897 2/1958Kreuttner 98-38 X OTHER REFERENCES Warren, R. W.: Wall effect and binarydevices. In proceedings of the uid amplification symposium, October1962, vol. l, pages 11-16 TP 156 F65 F5 1962 Sci. Library.

WLLIAM F. ODEA, Acting Primary Examiner.

EDWARD I. MICHAEL, Examiner.

6. CONTROLLABLE ASPIRATING APPARATUS FOR MAINTAINING A ROOM AT ACOMFORTABLE LIVING TEMPERATURE BY SUPPLYING AIR OF EXTREME TEMPERATUREMIXED WITH A GREATER AMOUNT OF AIR DRAWN FROM THE ROOM, COMPRISING ANOZZLE ADAPTED TO BE FED WITH SUPPLY AIR OF HIGH VELOCITY AND EXTREMETEMPERATURE, SAID NOZZLE HAVING A LONG AND NARROW ORIFICE OF A WIDTHLESS THAN 1/4 OF AN INCH FOR EJECTING THE SUPPLY AIR AS A FAST MOVINGLAYER, A CONTINUOUSLY CURVED CONVEX GUIDE SURFACE EXTENDING OUTWARDLYAWAY FROM SAID NOZZLE FROM AN INITIAL AREA ADJACENT TO ONE SIDE OF SAID